The automatic bagging of articles, particularly the automatic bagging of bruisable articles, such as apples, in a packing plant, must be done efficiently in order for a packer to optimize his return on investment. It is necessary that the packer ensure that all bags have at least a certain predetermined minimum weight, but have as little weight over that minimum as practical. It is also necessary to move the bag in a path from a filling position to an automatic tier in such a way that the tying action is performed in the most reliable and efficient manner possible. Further, in recent years the concern for the handling of the bruisable articles has dramatically increased, and it is desirable in modern packing plants to ensure that the bruisable articles are handled as gently as possible during the automatic bagging operation, consistent with effective bagging techniques.
According to the present invention, an automatic bagger, and method of automatically bagging articles, are provided which allow a packer to efficiently bag bruisable articles--such as apples--so that the bags produced have a minimum weight over a determined target, and in such a manner that the tying action is optimized for reliability and efficiency, and in such a manner such that the fruit, or other bruisable articles, are handled as gently as practical.
According to one aspect of the present invention, an automatic bagger is provided which includes a pan (such as a weigh pan having a load cell associated therewith) with a dump end, and a piston and cylinder assembly or the like for tilting the pan to dump articles therein into a bag. The bagger also includes a bag supply means and pneumatic means for supplying air to a bag from the bag supply to inflate the bag and maintain it open. Gripper means are provided for holding the bag while it is supplied with the air, adjacent the pan dump end. According to the invention, cushioning means--such as one or more cushioning arms--are provided for engaging the bag exterior as it is being filled with articles from the pan for cushioning the fall of the articles, along with power means--such as a piston and cylinder arrangement--for moving the cushioning means into engagement with the bag exterior while it is being filled, and away from the bag after the fall of articles has been effectively cushioned. The cushioning arms brake the fall of fruit into the bag at one or more points so that the maximum vertical drop in any one path is reduced compared to the prior art situation in which all of the apples were merely dumped into the open top.
The grippers engage the bag at two different portions thereof while it is being held open with a bag stretcher to receive articles, but then as the bag is being moved to operative association with an automatic tier, it is no longer engaged by the bag stretcher. The grippers are moved from the filling position to the automatic tier in a generally horizontal plane, and in an arcuate pathway such that the spaced locations of the grippers come closer together, and the top of the bag is at least slightly twisted to partially close during movement toward operative association with the automatic tier.
In order to minimize the "overage" of product in the bag, the articles are fed to the weighing pan or the like in a plurality of different, separately controller paths (e.g. three different conveyance paths). Once a first predetermined level under the desired weight of articles has been sensed, all feed of articles to the pan in momentarily arrested. After an equilibrium weight of the articles in the weight pan has then been determined, the volume of the next article or articles in each conveyance path is sensed--as by an ultrasound means--and the next article or articles of the conveyance path having a projected weight--based upon its volume--closest to just over the predetermined weight of articles in the pan, is sensed, and then the conveyance path or paths with that "closest" article or articles is or are operated momentarily so that the article or articles is or are conveyed into the pan. After equilibrium is again established, the sensing and selective conveyance path operation steps are repeated if necessary.
A wheel is mounted adjacent the automatic tier to assist in directing the bag, in its horizontal plane of movement, into operative association with the automatic tier. The combination of the wheel, horizontal plane of movement, and grippers provides effective, reliable, automatic tying.
According to another aspect of the present invention, a method of bagging bruisable articles is provided. That method comprises the steps of automatically and substantially sequentially: (a) Inflating a plastic bag with air while holding it adjacent an open top thereof. (b) Dropping bruisable articles into the open top of the bag. (c) Cushioning the drop of bruisable articles into the bag by effectively reducing the height of drop of articles in any continuous vertical path. And, (d) tying the bag open top closed when the bag is full. Step (d) is preferably practiced by moving the bag in a horizontal plane from a position at which it is filled to an automatic tying machine; preferably by at least partially twisting the bag so that the open top thereof at least partially closes as the bag is moved from the filling position to the automatic tier.
The invention also contemplates a method of bagging articles by automatically and substantially sequentially practicing the steps of: (a) Inflating a plastic bag while holding it adjacent its open top. (b) Dropping articles into the bag at a filling position. (c) Moving the articles and the bag from the filling position, in a horizontal plane, while simultaneously at least slightly twisting the open of the bag, from the filling position to a tying position. And, (d) tying the open top of the bag closed at the tying position.
The invention also contemplates a method of bagging articles by automatically and substantially sequentially practicing the steps of: Inflating a plastic bag while holding it adjacent an open top thereof. Feeding articles to be bagged in a plurality of conveyance paths to a weighing mechanism. Once an initial weight close to, but not at, the selected weight has been reached, momentarily stopping the conveyance of articles to the weighing mechanism. Sensing the next article or articles in the plurality of conveyance paths which is or are of incremental value closest to the pre-selected weight and the actual weight of articles in the weighing mechanism. Conveying that selected article or articles into the weighing mechanism. Once the pre-selected weight, or an amount slightly greater than the pre-selected weight, has been reached, dropping the articles from the weighing mechanism into the open top of the bag. And, tying the open top of the bag closed.
It is the primary object of the present invention to provide for the simple yet effective and gentle automatic bagging of articles, particularly bruisable articles such as fruits and vegetables. This and other objects of the invention will become clear from an inspection of the detailed description of the invention, and from the appended claims.